Severe Anthropogenic Disturbances Research Articles

Saharo-Sindian endemic flora of Egypt: critical checklist, floristic analysis, habitats, and phytogeographic distribution

The Saharo-Sindian region is characterized by savannas, semi-deserts, and hot deserts. This floristic region includes Morocco, Mauretania, Algeria, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, United Arab Emirates, Oman, Yemen, South of Jordan, Syria, Iraq, Afghanistan, Pakistan, in addition to the Sind region. The Sudano-Zambezian region, part of the Paleotropical Kingdom, and the Mediterranean and Irano-Turanian regions, included in the Holarctic Kingdom, share a significant portion of their flora with the studied region. This study initiates the examination of the Saharo-Sindian endemic plants occurring in Egypt. Its objectives include assessing the list of endemic plants within this floristic region, and studying various aspects such as: life forms, habitats, rarity forms, flowering times, dispersal types, and phytogeographical distribution. Twenty field trips were conducted from spring 2020 to September 2023, investigating different regions in Egypt. In addition, all the previous studies performed in the investigated area, scientific literature, and specimens from the region housed in different herbaria have been taken into consideration. The inventory of plants that are endemic to the Saharo-Sindian floristic region in Egypt comprises 126 plant taxa (109 species, 17 subspecies) distributed across 87 genera and 37 families. These endemics are found in 11 habitat types, with the most abundant occurrences observed in inland rocky areas (82 taxa) and temperate shrublands (57 taxa). Moreover, South Sinai stands out as the richest region for Saharo-Sindian endemics, hosting a remarkable 83 taxa, which constitute 65.9% of the total endemics. Among these, the chamaephytes group leads with 56 taxa, followed by the therophytes with 32 taxa. Pogonochores (45 taxa) are the most represented dispersal type. This study holds significant importance in evaluating a critical checklist of plants endemic to the Saharo-Sindian region in Egypt, contributing to our understanding of species diversity in regions facing severe anthropogenic disturbance. This list provides a foundational reference for future monitoring programs.

Changes in assembly processes and differential responses of soil microbial communities during mining disturbance in mining reclamation and surrounding grassland

Soil microbes play critical roles in regulating ecosystem-level functioning and responding to environmental changes after disturbance events. However, a systematic understanding of soil microbial community assembly processes and responses in the context of severe anthropogenic disturbance remains lacking. Here, microbial communities collected from the soil in the mining reclamation and surrounding grassland of the Baiyinhua #1 open-pit coal mine were profiled and compared by three-generation PacBio sequencing to identify the response characteristics of the soil microbial communities to mining-induced disturbance, microbial community assembly and their relevance to environmental variables. The results suggested that the five locations surveyed had heterogeneous microbial community structures, distribution patterns and network topological characteristics, especially exhibiting contrasting differences between the mining reclamation and the grassland surrounding the mine, and different survey sites supported the enrichment of different and adaptative bacterial and fungal taxa and biomarkers. In comparison to the bacterial community, the fungal community was more susceptible to the current mining disturbances, and the stability of the core fungal interaction network, fungal diversity and resistance index were relatively low. Redundancy analysis showed that the differences in microbial communities were driven by the joint impacts of soil alkaline phosphatase and total nitrogen, and differences in bacterial communities were also driven by pH. Stochastic processes dominated the microbial assemblies at the entire site across the mining reclamation and grasslands around the coal mine, and dispersal limitation and drift were the dominant processes of the bacterial and fungal assemblies, respectively, at most individual sites. The relative influences of deterministic and stochastic processes in terms of shaping microbial community assemblies shifted with soil enzyme activity and nutrients. These findings provide critical insights into the prediction of soil ecosystem recovery after disturbance and deepen our understanding of the responses and assembly rules associated with severe anthropogenic disturbance.

Planting methods influence revegetation success of native species in an arid environment

In Kuwait, declining native vegetation cover due to prevailing arid conditions and severe anthropogenic disturbances necessitated undertaking revegetation programs. Seed sowing and outplanting of nursery-grown seedlings are the two major plant establishment methods commonly used all around the world. However, the success of plant establishment methods may vary between the species as well as between the methods. Therefore, we compared the effect of sowing of primed or non-primed seeds and outplanting of nursery-grown seedlings on field performance of four dominant native desert species of Kuwait: Vachellia pachyceras, Rhanterium epapposum, Farsetia aegyptia, and Haloxylon salicornicum for 22 months to find the best method for revegetation in arid conditions. A significant species and treatment interaction effect was observed in all plant parameters except plot volume index. Direct sowing of hydro-primed seeds appeared to be the most effective method for establishment and growth of V. pachyceras. In contrast, outplanting of nursery-grown seedlings showed better performance under the field conditions in H. salicornicum and F. aegyptia. These results suggest that direct sowing of primed seeds can also be used effectively along with seedling outplanting for the revegetation of arid lands.

Floristic Composition and Structural Analysis of Woody Plant Species in Jib Godo Natural Forest, Farta District, South Gonder Zone, Amhara Region, Ethiopia

Afromontane forests are crucial for maintaining plant diversity and reducing climate change. Even though the Jib Godo Natural Forest is subject to anthropogenic impacts such as cutting and farming, it lacks long-term conservation practices. The researchers conducted fieldwork in Jib Godo Natural Forest to investigate the floristic composition and structural analyses of woody plant species in Ethiopia. The vegetation and environmental data were collected from 50 (20 m × 20 m) sample plots established for woody species at every 100 m along seven transect lines and 5 m × 5 m in five subplots for saplings and seedlings using a systematic sampling procedure. In each sample plot, soil samples were obtained from 0–20 cm and mixed to generate a composite sample. A vegetative structural analysis of DBH, height, and stem IVI was computed. There were 65 species of woody plant identified, belonging to 58 genera and 41 families, with 34 species (52.30 percent) being trees, 23 species (35.38 percent) being shrubs, and 8 species (12.30 percent) being lianas. Outside of the sample plot, four other species were identified. Only eleven environmental characteristics were significant at p < 0.05, according to the results of canonical correspondence analysis (CCA). In conclusion, the distribution of plant communities and the composition of the species depend on altitude and topographic aspects. The forest’s population structure and regeneration condition suggested that the area had experienced forest degradation and severe anthropogenic disturbances; therefore, the conservation of species and sustainable use of forest genetic resources are advocated as a result of this study’s findings.

Seasonal succession of microbial community co-occurrence patterns and community assembly mechanism in coal mining subsidence lakes.

Coal mining subsidence lakes are classic hydrologic characteristics created by underground coal mining and represent severe anthropogenic disturbances and environmental challenges. However, the assembly mechanisms and diversity of microbial communities shaped by such environments are poorly understood yet. In this study, we explored aquatic bacterial community diversity and ecological assembly processes in subsidence lakes during winter and summer using 16S rRNA gene sequencing. We observed that clear bacterial community structure was driven by seasonality more than by habitat, and the α-diversity and functional diversity of the bacterial community in summer were significantly higher than in winter (p < 0.001). Canonical correspondence analysis indicated that temperature and chlorophyll-a were the most crucial contributing factors influencing the community season variations in subsidence lakes. Specifically, temperature and chlorophyll-a explained 18.26 and 14.69% of the community season variation, respectively. The bacterial community variation was driven by deterministic processes in winter but dominated by stochastic processes in summer. Compared to winter, the network of bacterial communities in summer exhibited a higher average degree, modularity, and keystone taxa (hubs and connectors in a network), thereby forming a highly complex and stable community structure. These results illustrate the clear season heterogeneity of bacterial communities in subsidence lakes and provide new insights into revealing the effects of seasonal succession on microbial assembly processes in coal mining subsidence lake ecosystems.

Multivariate drives and their interactive effects on the ratio of transpiration to evapotranspiration over Central Asia ecosystems

The ratio of vegetation transpiration to evapotranspiration (T/ET) characterizes the role of vegetation in surface-atmosphere interactions, affecting ecosystem productivity and the global carbon and water balances. Therefore, isolating and identifying the spatiotemporal characteristics of T/ET and its response to the individual and interactive effects of climatic factors will help us better understand the carbon and water cycle characteristics of ecosystems. The arid region of Central Asia has always been in the restricted area of ​​carbon-water cycle observations due to scarce station observations, harsh climatic conditions, and severe anthropogenic disturbances. Using a specific Arid Ecosystem Model (AEM), this study explored the temporal and spatial dynamic patterns of T/ET of different plant functional types (PFTs) in drylands of Central Asia based on multi-climate scenarios, and separated and quantified the independent and interactive effects of different environmental factors. The result indicated that precipitation dominated the areas of 86% (ET, evapotranspiration), 77% (T, transpiration), and 71% (the ratio of T/ET) in the arid region of Central Asia, respectively. The effect of temperature on the ratio of T/ET was negative and slight. And the temperature increase effect is only 9.7% of the negative effect of precipitation. Affected by the insignificant effect of CO2 enrichment on T, the interactive effect between climate change and CO2 effect appear to be little and negative. According to the vegetation growth and the spatial distribution of precipitation, we found that the southern Xinjiang region and the Turgay Plateau in northwestern Kazakhstan are the ecologically vulnerable areas in Central Asian. The results also indicated that general warming in this region may not have a direct and significant impact on vegetation T/ET in the future. We may need to pay more attention to the indirect effect of enhanced evaporation and reduced moisture on T/ET caused by future warming.

The Status of Dry Evergreen Afromontane Forest Patches in Amhara National Regional State, Ethiopia

Ethiopian dry evergreen afromontane forests are primary biodiversity priority areas including many forest patches of Amhara Region. Natural vegetation of the region is now almost exclusively limited to sacred places, very few protected and less accessible areas. Despite different studies on the various dry evergreen afromontane forest patches of the region, there was not a review work on these forest patches at a regional level. Lack of comprehensive review work creates ambiguity to the understanding of the current status of the forest patches. Scientific information on these forest patches is important for future managerial intervention and sustainable utilization. Thus, the review was aimed to evaluate the status of dry evergreen afromontane forest patches of the Region. Each forest patch contained 15–156 plant species with a total of 525 species under 328 genera and 112 families. Asteraceae was the most species richest family followed by Fabaceae. Most patches harbored considerable number of endemic plant species with a total of 46 species within 44 genera and 26 families. Asteraceae was the most endemic species rich family. Most forest patches had high diversity. Diameter at breast height (DBH) and height class analyses of most forest patches revealed an inverted J-shape pattern. Mean basal area of the forest patches ranged from 1 m2h−1 to 115.36 m2h−1. In most forest patches many number of species were put in low frequency classes. The forests had more seedlings and/or saplings than mature individuals. Although each patch had a rich source of biodiversity, it is influenced by severe anthropogenic disturbances. Therefore, appropriate managerial interventions are required.

Separating natural from human enhanced methane emissions in headwater streams

Headwater streams are natural sources of methane but are suffering severe anthropogenic disturbance, particularly land use change and climate warming. The widespread intensification of agriculture since the 1940s has increased the export of fine sediments from land to streams, but systematic assessment of their effects on stream methane is lacking. Here we show that excess fine sediment delivery is widespread in UK streams (n = 236) and, set against a pre-1940s baseline, has markedly increased streambed organic matter (23 to 100 g m−2), amplified streambed methane production and ultimately tripled methane emissions (0.2 to 0.7 mmol CH4 m−2 d−1, n = 29). While streambed methane production responds strongly to organic matter, we estimate the effect of the approximate 0.7 °C of warming since the 1940s to be comparatively modest. By separating natural from human enhanced methane emissions we highlight how catchment management targeting the delivery of excess fine sediment could mitigate stream methane emissions by some 70%.

Factors influencing habitat choice of bird species: a comparative study of the ornithofauna of a natural and an artificial wetland

Between 2019 and 2022, we studied the avifauna and environmental conditions of two wet-land habitats located in close proximity to each other in Transcarpathia (nearby to the village of Dyida, Zakarpatska Oblast, Ukraine)—one being a natural, currently protected but drying and highly degraded former bog (Tóvár Ornithological Reserve), whereas the other one being an ar-tificial pit lake (Lake Dyida). Lake Dyida is used as a beach and recreation area during the summer nesting season of birds. Both of these wetlands border with agricultural lands. Bird species that occur in both of the investigated habitats are affected by severe anthropogenic disturbances. A total of 27 795 individuals of 58 bird species from 34 families were observed in the two areas over the four study years. Results indicate that the species composition of the two study sites differed considerably, both on annual and seasonal basis. Seasonal precipitation totals strongly influence the current spatial ratios of terrestrial and waterbird species, and show a strong positive correlation with the seasonal total number of bird species. Maximum numbers of birds are recorded in spring and summer at Tóvár and in autumn and winter at Lake Dyida. In the case of Lake Dyida, these could partly be due to the autumn–winter appearance of migratory waterbirds and the end of the beach season. Despite the impact of numerous anthro-pogenic factors and habitat distrubances, the natural wetland is much more species-rich even in its degraded condition than the artificial wetland, which has been confirmed not only for bird species but also for plant species in the two areas. The obtained results revealed that duck spe-cies consider the deep-water pit lake as an alternative habitat during periods of drought, but for waders the great water depth makes this site less exploitable. In Europe, too, drying out due to seasonal precipitation shortages is an issue of increasing concern, especially for wetlands bea-cuse artificially maintained lakes and reservoirs cannot fully take over the role of natural lakes, marshes and bogs, which will have severe consequences for nature protection and species con-servation in the future.

Community assembly during vegetation succession after metal mining is driven by multiple processes with temporal variation.

The mechanisms governing community assembly is fundamental to ecological restoration and clarification of the assembly processes associated with severe disturbances (characterized by no biological legacy and serious environmental problems) is essential. However, a systematic understanding of community assembly in the context of severe anthropogenic disturbance remains lacking. Here, we explored community assembly processes after metal mining, which is considered to be a highly destructive activity to provide insight into the assembly rules associated with severe anthropogenic disturbance. Using a chronosequence approach, we selected vegetation patches representing different successional stages and collected data on eight plant functional traits from each stage. The traits were classified as establishment and regenerative traits. Based on these traits, null models were constructed to identify the processes driving assembly at various successional stages. Comparison of our observations with the null models indicated that establishment and regenerative traits converged in the primary stage of succession. As succession progressed, establishment traits shifted to neutral assembly, whereas regeneration traits alternately converged and diverged. The observed establishment traits were equal to expected values, whereas regenerative traits diverged significantly after more than 20 years of succession. Furthermore, the available Cr content was linked strongly to species' ecological strategies. In the initial stages of vegetation succession in an abandoned metal mine, the plant community was mainly affected by the available metal content and dispersal limitation. It was probably further affected by strong interspecific interaction after the environmental conditions had improved, and stochastic processes became dominant during the stage with a successional age of more than 20 years.

Gap dynamics and disease-causing invasive species drive the development of an old-growth forest over 250 years

Investigating the disturbance regimes of unharvested forests helps us understand their past, present, and future trajectory and gives us a model for forest management. It can also clarify the relative importance of small-scale gap dynamics versus more severe disturbances. Here we used tree rings to examine the recruitment patterns, growth dynamics, and disturbance chronologies of American beech (Fagus grandifolia), sugar maple (Acer saccharum), and eastern hemlock (Tsuga canadensis) in A.B. Williams Woods, an old-growth forest in Ohio, USA, over the past 250 years. We found that beech and sugar maple recruitment peaked around 1900 and continued through the 1900s, while hemlock recruitment peaked during 1825–1875, then declined and effectively ended in the early 1900s. Hemlock grew fastest during the 1800s according to ring width and basal area increment, while sugar maple ring width surpassed beech and hemlock in the 1900s. All three species showed a dramatic increase in growth from 1980 to 2010. Beech and sugar maple established regardless of canopy gaps, but 73% of hemlocks originated in gaps. In most decades, <10% of trees experienced gap recruitment or growth release, suggesting that ongoing, endogenous canopy mortality was the primary disturbance shaping this forest. However, a more severe forest-wide disturbance occurred during the 1980s–1990s when the scale insect causing beech bark disease was introduced, with greater than 30% of living trees showing growth releases in those decades. Another synchronous release occurred in the 1930s when blight-killed chestnuts were removed; 16% of trees showed releases. Both of these intermediate-severity disturbances involved human introduction of invasive species. Thus, we documented a natural disturbance regime of small-scale gap dynamics, punctuated by more severe anthropogenic disturbances in the twentieth century. These relatively frequent, intermediate-severity events probably mean that the forest’s current composition is non-equilibrial. Hemlock may continue to decline while beech maintains its dominance by constant regeneration in both gaps and shade, and by responding to disturbance with root suckering and growth pulses. The codominance of sugar maple may be relatively recent, and perhaps temporary, as we found little sugar maple recruitment before 1875 or after 1950, and three times fewer sugar maple saplings now than in the early 1900s. Despite being protected as a park, the development of this old-growth forest has been shaped more by disease-causing invasive species than natural disturbances over the past century. This result emphasizes the pervasiveness of human impacts even in communities we look to as examples of natural pattern and process.

Effects of severe anthropogenic disturbance on the heart rate and body temperature in free-living greylag geese (Anser anser).

Anthropogenic disturbances are a major concern for the welfare and conservation of wildlife. We recorded heart rate and body temperature of 20 free-living greylag geese in response to a major regularly re-occurring anthropogenic disturbance—New Year’s Eve fireworks. Heart rate and body temperature were significantly higher in the first and second hour of the new year, compared with the same hour on the 31st of December, the average during December and the average during January. Heart rate and body temperature was not significantly affected by sex or age. From 0200 to 0300 onwards, 1st of January heart rates did not significantly differ from the other periods; however, body temperatures were significantly increased until 0300–0400. From 0400 to 0500, heart rate was not affected by any of the investigated factors, whereas body temperature was significantly increased on the 1st of January compared with the 31st of December and the December average but not compared with the January average. To conclude, our results show that New Year’s Eve fireworks cause a substantial physiological response, indicative of a stress response in greylag geese, which is costly in terms of energy expenditure.

Nitrogen cycling in a tropical coral reef ecosystem under severe anthropogenic disturbance in summer: Insights from isotopic compositions

Coral reefs, one of the most productive ecosystems, have been dramatically declining in recent decades. While studies contend a prominent correlation between coral reef degradation and increased anthropogenic nitrogen (N) loads, a quantitative description of the N sources and cycling processes in these ecologically important ecosystems is lacking. Through a comprehensive depiction of the δ15N compositions of seawaters and sediments, we systematically accessed the N cycling processes in the Weizhou coral reef ecosystem. The correlations between the nitrate (NO3−) concentrations and isotopic compositions (δ15N/δ18O-NO3−) indicated the pelagic NO3− loads were largely regulated by mixing between precipitation and sewage. Biological NO3− turnover processes appeared to be weak. In the sediments, N2 fixation contributed about one-third of the sedimentary organic N, with the rest coming from the settlement of pelagic organic N. We also uncovered significant sedimentary mineralization-nitrification-denitrification processes in which the N loss was greater than the input. While pelagic N significantly contributed to the sedimentary N, the N export from the sediments to surface seawater was potentially short-circuited by the high N retention and recycling efficiencies of the organisms in the coral reef ecosystem. Overall, this study shows that the complex N cycling processes in the ecosystem are effectively reflected in the isotopic compositions of seawater and sediment, thus adding an important dimension to understanding the N cycling in coral reef ecosystems.

Restoration ecophysiology: an ecophysiological approach to improve restoration strategies and outcomes in severely disturbed landscapes

As human activities destroy and degrade the world's ecosystems at unprecedented scales, there is a growing need for evidence‐based methods for ecological restoration if we are to preserve biodiversity and ecosystem services. Mining represents one of the most severe anthropogenic disturbances, often necessitating intensive intervention to restore the most basic attributes of native ecosystems. Despite examples of successful mine‐site restoration, re‐establishing native vegetation in these degraded landscapes remains a significant challenge. Plant ecophysiology—the study of the interactions between plants and the environment—can provide a useful framework for evaluating and guiding mine‐site restoration. By understanding the physiological mechanisms that allow plants to establish and persist in these highly disturbed environments, practitioners may be able to improve restoration outcomes. Specifically, methods in plant ecophysiology can inform site preparation and the selection of plant material for restoration projects, aid in monitoring restoration progress by providing additional insight into plant performance, and ultimately improve our ability to predict restoration trajectories. Here, we review the challenges and benefits of integrating an ecophysiological perspective to mine‐site restoration in Western Australia, a global hotspot of biodiversity and mining operations. Using case studies and examples from the region's diverse ecosystems, we illustrate how an ecophysiological approach can guide the restoration of some of the world's most severely disturbed landscapes. With careful selection of study species and traits and consideration of the specific environmental conditions and stressors within a site, the restoration ecophysiology framework outlined here has the potential to inform restoration strategies across ecosystems.

Hydrogeological Modeling of the Spread of Pollution from the Historical Landfill Towards the Lakhta Spill, St. Petersburg, Russia

Nowadays, the areas subjected to severe anthropogenic disturbance, such as waste landfills, do not meet both the environmental and human health standards and are associated with concepts of "environmental degradation", "pollution" and "environmental risk". In turn, the geochemical influence is associated with almost all types of technogenesis, has a widespread occurrence, occurs during the entire period of use of the territory and affects all components of the natural complex. Taking into account both geological and hydrogeological features of the study areas, predictions of contaminants migration from the historical waste landfills of St. Petersburg to the catchment area of the Gulf of Finland have been compiled. The results demonstrated the usefulness of a step-by-step method, involving increasingly detailed geochemical "portraits" of anthropogenically modified objects, as well as the creation of training geochemical set to predict the changes of functional zones contour.

Anthropogenic disturbance and chimpanzee (Pan troglodytes) habitat use in the Masito-Ugalla Ecosystem, Tanzania

Abstract The habitat quality of chimpanzee (Pan troglodytes), including the availability of plant food and nesting species, is important to ensure the long-term survival of this endangered species. Botanical composition of vegetation is spatially variable and depends on soil characteristics, weather, topography, and numerous other biotic and abiotic factors. There are few data regarding the availability of chimpanzee plant food and nesting species in the Masito-Ugalla Ecosystem (MUE), a vast area that lies outside national park boundaries in Tanzania, and how the availability of these resources varies with human disturbance. We hypothesized that chimpanzee plant food species richness, diversity, and abundance decline with increasing human disturbance. Further, we predicted that chimpanzee abundance and habitat use is influenced negatively by human disturbance. Published literature from Issa Valley, Gombe, and Mahale Mountains National Parks, in Tanzania, was used to document plant species consumed by chimpanzees, and quantify their richness, diversity, and abundance, along 32 transects totaling 63.8 km in length across four sites of varying human disturbance in MUE. We documented 102 chimpanzee plant food species and found a significant differences in their species richness (H = 55.09, P &amp;lt; 0.001) and diversity (H = 36.81, P &amp;lt; 0.001) across disturbance levels, with the moderately disturbed site exhibiting the highest species richness and diversity. Chimpanzees built nests in 17 different tree species. The abundance of nesting tree species did not vary across survey sites (H = 0.279, P &amp;gt; 0.964). The least disturbed site exhibited the highest encounter rate of chimpanzee nests/km, with rates declining toward the highly disturbed sites. Our results show that severe anthropogenic disturbance in MUE is associated with the loss of chimpanzee plant food species and negatively influences chimpanzee habitat use, a relationship that threatens the future of all chimpanzee populations outside national parks.

Disturbance mechanisms of lacustrine organic carbon burial: Case study of Cuopu Lake, Southwest China

Lakes are important organic carbon (OC) traps in the global carbon cycle. Recent studies have shown that the rate of OC burial in lacustrine sediments is influenced by factors such as climate change, land-use change, and eutrophication. In this study, we use multiproxy methods to reveal the mechanisms of lacustrine sediment OC burial in an alpine lake (Cuopu Lake), in southwest China. Combined with the dating from 210Pbex and n-alkanes distribution analysis using the Positive Matrix Factorization model, the sedimentary history was divided into five stages: religious activity (the 1840s–1880s), earthquake (the 1880s–1910s), garrison (the 1910s–1960s), transition (the 1960s–1990s), and ecotourism (the 1990s–2010s). During the earthquake stage, OC burial was dominated by terrestrial solids (>40%) and co-precipitated algae (>30%), with a rapid deposition rate (>4 mm a−1) and low OC concentration (<4 mg g−1). During the other stages, when the level of disturbance was relatively low, a change in nutrient conditions either promoted or inhibited plant growth, which influenced the type of buried OC. The contribution of OC derived from combustion sources varied from stage to stage. Severe anthropogenic disturbances have led to a significant increase in nutritional levels in the lake water, leading to an increase in the OC burial rate. Climate change, which leads to changes in temperature and rainfall, did not significantly influence OC burial, whereas nitrogen deposition (and associated ecological changes) was a significant determinant. When the general mechanism is dominant, the total nitrogen to inorganic phosphorus ratio is an effective indicator of OC burial due to its selective promotion of different plant types. In conclusion, our results suggest that lacustrine sediment OC burial is closely linked to physical and anthropogenic factors in Cuopu Lake, as well as similar montane lakes.

Fine-scale genetic structure and flowering output of the seagrass Enhalus acoroides undergoing disturbance.

Seagrass are under great stress in the tropical coast of Asia, where Enhalus acoroides is frequently the dominant species with a large food web. Here, we investigate the question of the fine‐scale genetic structure of this ecologically important foundation species, subject to severe anthropogenic disturbance in China. The genetic structure will illuminate potential mechanisms for population dynamics and sustainability, which are critical for preservation of biodiversity and for decision‐making in management and restoration. We evaluated the fine‐scale spatial genetic structure (SGS) and flowering output of E. acoroides, and indirectly estimated the relative importance of sexual versus asexual reproduction for population persistence using spatial autocorrelation analysis. Results reveal high clonal diversity for this species, as predicted from its high sexual reproduction output. The stronger Sp statistic at the ramet‐level compared with genet‐level indicates that clonality increases the SGS pattern for E. acoroides. Significant SGS at the genet‐level may be explained by the aggregated dispersal of seed/pollen cohorts. The estimated gene dispersal variance suggests that dispersal mediated by sexual reproduction is more important than clonal growth in this study area. The ongoing anthropogenic disturbance will negatively affect the mating pattern and the SGS patterns in the future due to massive death of shoots, and less frequency of sexual reproduction.

Montane peat bog records of vegetation, climate, and human impacts in Fujian Province, China, over the last 1330 years

We used pollen and grain-size data from a peat bog in Xiansan, Fujian Province, southeastern China, to reconstruct a high-resolution record of vegetation change, climatic dynamics, and human impact over the last 1330 cal BP. During 1330–1200 cal BP, we infer the existence of a swamp bog with dense cypress forests, based on dominant Cupressaceae pollen, suggesting cold and dry conditions during this early period. Fine-grained sediment and higher percentages of wetland pollen and fern spores suggest intermittent-lake conditions, indicating a wet Medieval Warm Period (MWP; 1200–730 cal BP). The increase in coniferous forest and montane shrub-meadow pollen indicate a cold and dry climate during the early to mid-Little Ice Age (LIA; 730–370 cal BP), but coarse-grained sediments associated with more abundant wetland taxa pollen indicate a shallower intermittent-lake landscape, reflecting relatively humid periods during 620–560 cal BP and 400–450 cal BP. During the last 370 cal BP, a rapid increase in the secondary forest component and a gradual decrease in the pollen-inferred floristic diversity index suggest that the natural vegetation was converted to secondary vegetation, as a result of severe anthropogenic disturbance in the montane region of Fujian Province. The reconstructed regional precipitation trend prior to this period was mainly correlated with East Asian summer monsoon (EASM) intensity, which is related to variation in solar irradiation.

Restoring forests: regeneration and ecosystem function for the future

Conventions and policies for biodiversity conservation and climate change mitigation state the need for increased protection, restoration and climate change adaptation of forests. Much degraded land may be targeted for large-scale forest restoration, yet challenges include costs, a shortage of regeneration material and the need for restored forests to serve as a resource for communities. To ensure ecosystem function for the future, forest restoration programs must: (1) learn from the past; (2) integrate ecological knowledge; (3) advance regeneration techniques and systems; (4) overcome biotic and abiotic disturbances and (5) adapt for future forest landscapes. Historical forest conditions, while site-specific, may help to identify the processes that leave long-term legacies in current forests and to understand tree migration biology/population dynamics and their relationship with climate change. Ecological theory around plant–plant interactions has shown the importance of negative (competition) and positive (facilitation) interactions for restoration, which will become more relevant with increasing drought due to climate change. Selective animal browsing influences plant–plant interactions and challenges restoration efforts to establish species-rich forests; an integrated approach is needed to simultaneously manage ungulate populations, landscape carrying capacity and browse-tolerant regeneration. A deeper understanding of limiting factors that affect plant establishment will facilitate nursery and site preparation systems to overcome inherent restoration challenges. Severe anthropogenic disturbances connected to global change have created unprecedented pressure on forests, necessitating novel ecological engineering, genetic conservation of tree species and landscape-level approaches that focus on creating functional ecosystems in a cost-effective manner.